1. Field of the Invention
The present invention relates to an optical disc, a video data editing apparatus, a computer-readable recording medium that stores an editing program, a reproduction apparatus for the optical disc, and a computer-readable recording medium that stores a reproduction program.
2. Description of the Background Art
Video editors in the film and broadcasting industries make full use of their skill and experience when editing the great variety of video productions that reach the market. While movie fans and home video makers may not possess such skill or experience, many are still inspired by professional editing to try video editing for themselves. This creates a demand for a domestic video editing apparatus that can perform advanced video editing while still being easy to use.
While video editing generally involves a variety of operations, domestic video editing apparatuses that are likely to appear on the market in the near future will especially require an advanced scene linking function. Such function links a number of scenes to form a single work.
When linking scenes using conventional domestic equipment, the user connects two video cassette recorders to form a dubbing system. The operations performed when linking scenes using this kind of dubbing system are described below.
FIG. 1A shows a video editing setup using video cassette recorders that are respectively capable of recording and playing back video signals. The setup of FIG. 1A includes the video cassette 301 that records the source video, the video cassette 302 for recording the editing result, and two video cassette recorders 303 and 304 for playing back and recording video images on the video cassettes 301 and 302. In this example, the user attempts to perform the editing operation shown in FIG. 1B using the setup of FIG. 1A.
FIG. 1B shows the relationship between the material to be edited and the editing result. In this example, the user plays back scene 505 that is located between time t5 and time t10 of the source material, scene 506 that is located between time t13 and t21, and scene 507 that is located between time t23 and t25 and attempts to produce and editing result that is only composed of these scenes.
With the setup of FIG. 1A, the user sets the video cassette 301 including the source material into the video cassette recorder 303 and the video cassette 302 for recording the editing result into the video cassette recorder 304.
After setting the video cassettes 301 and 302, the user presses the fast-forward button on the operation panel of the video cassette recorder 303 (as shown by {circle around (1)} in FIG. 1A) to search for the start of scene 505. Next, the user presses the play button on the operation panel of the video cassette recorder 303 (as shown by {circle around (2)} in FIG. 1A) to reproduce scene 505. At the same time, the user presses the record button on the operation panel of the video cassette recorder 304 (as shown by {circle around (3)} in FIG. 1A) to commence recording. When scene 505 has finished, the user stops the operation of both video cassette recorders 303 and 304. The user then fast-forwards the video cassette to the start of scene 506, and then simultaneously commences the playback by video cassette recorder 303 and the recording by video cassette recorder 304. After completing the above process for scenes 506 and 507, the user has the video cassette recorders 303 and 304 respectively rewind the video cassettes 301 and 302 to complete the editing operation.
If the scene linking operation described above could be performed with ease at the home, users would then be able to easily manage programs that have been recorded on a large number of magnetic tape cassettes.
A first problem with the video editing setup described above though is that the source material and editing result need to be recorded on separate recording media, meaning that two video cassette recorders need to be used for playing back and recording the respective recording media. This greatly increases the scale of the video editing setup. Since video editing can only be performed in a place where it is possible to connect two video cassette recorders, this means that a large space is required to perform the editing operation.
A second problem with the video editing setup described above is that when the user wishes to perform a scene linking operation, the user has to repeat the processes of locating the start of the desired scene and reproducing all of the video images from the beginning to the end of the scene for each scene to be linked. Here, the larger the number of scenes to be linked, the greater the burden of locating the start of each scene and reproducing the scene, meaning that the complex operations end up taking a considerable amount of time.
When a professional editor performs scene linking, instead of producing the editing result in one attempt, it is common for the editor to repeatedly amend the scene linking order so that high-quality results can finally be achieved. When using a setup where locating the start and reproducing scenes takes so much trouble, it is very difficult to perform such repeated amendment of the scene linking order.
These problems can be thought of as being caused by the use of magnetic tape as the recording medium, so that improvements could be made by using a video editing setup that utilizes a recording medium which allows random access, such as a hard disc or phase change-type optical disc.
As one example, if an optical disc were used to store the editing material and the editing result could be stored on the same optical disc, video editing would then be possible using only one video data editing apparatus that uses an optical disc as a recording medium, thereby greatly reducing the scale of the editing equipment. However, if both the editing source material and editing result are stored on the same optical disc, there can be cases when the editing result ends up being overwritten over the editing source material. In such a case, if the editor later wishes to change the editing result, the source material will have been overwritten, meaning that the editor will not be able to redo the editing using the original source materials.
When the editing source materials are of great personal value, such as footage of a child""s school entrance ceremony, a school sports day, a family holiday, or a graduation ceremony, the overwriting of the source materials denies the user the chance to watch such important events again, let alone the chance to re-edit them. If the recording medium has a capacity that is greater than double the size of the source materials, an editing operation could presumably be performed without overwriting the source materials. However, for phase-change optical discs that are the most advanced recording medium, the recording capacity is still only 2.6 GB on one side, so that it is not possible to record video images with a reproduction time of greater than two hours separately as source materials and editing results. Also, if the user wishes to create several intermediate versions and record these separately on the optical disc to allow the selection of the best one at a later date, a recording disc with three or four times the date size of the audio video data (data produced by multiplexing video data and audio data) will be required. It can therefore be readily understood that the storage capacity of a single disc is insufficient.
A third problem with the video editing setup described above is that the sections to be linked cannot be precisely indicated. When performing the editing shown in FIG. 1A, the user needs to press the play button of one video cassette recorder at the same time as the record button on the other video cassette recorder. If the user presses one of these buttons before the other, there is the problem that an undesired part will end up in the recording result, or that the editing result will not include the start of the desired part.
It is a first object of the present invention to provide an optical disc and a video data editing apparatus that uses the optical disc as a recording medium, the optical disc enabling video that is already recorded on the disc to be edited on the disc itself without overwriting.
It is a second object of the present invention to provide an optical disc and a video data editing apparatus that uses the optical disc as a recording medium, the optical disc being able to store not merely a final result of video editing, but also a number of separate intermediate video editing patterns, with the user being able to select a most suitable of the intermediate video editing patterns at a later date.
It is a third object of the present invention to provide an optical disc and a reproduction apparatus for the optical disc, the optical disc allowing the user to indicate sections that are to be subject to editing with high precision during the display of video images.
The first object and second object can be achieved by an optical disc, including: a data area for recording a file including at least one video object; and an index area for recording original type chain information and at least one set of user-defined type chain information, the original type chain information managing the file as an arrangement of a plurality of file sections, each file section being indicated by section boundaries that are a combination of any two ofxe2x80x94(a) a start position of a video object, (b) an end position of a video object, and (c) at least one predetermined position within a video object, each set of user-defined type chain information indicating a plurality of file parts in the file and a reproduction route for the indicated file parts, each file part being indicated by part boundaries, the part boundaries being any ofxe2x80x94(a) two of the section boundaries, (b) one of the section boundaries and a position in a video object that differs from the predetermined positions, (c) two positions in a video object that differ from the predetermined positions, each reproduction route being independent of an order in which the indicated file parts appear in the file.
The original type chain information can indicate that sections are produced in the order in which they are arranged in a video object. The user-defined type chain information can indicate a provisionally decided reproduction route for a work produced by video editing of the plurality of sections included in a video object.
The original type chain information can indicate the finally determined reproduction order when a video object in the data area is processed by a video data editing apparatus in accordance with a set of user-defined type chain information, or when the video object in the data area is overwritten.
The chain information is used during editing operations, so that the user can soon generate reproduction routes for his/her desired sequences of scenes by defining sets of user-defined type chain information. By reproducing video in accordance with a set of user-defined type chain information, the user is able to verify the content of a provisionally determined reproduction route.
This provisional determination of a reproduction route can be easily performed in a short time by defining a set of user-defined type chain information. Since the data size of a set of user-defined type chain information is negligible, there is no risk of the video object being accidently overwritten by a set of user-defined type chain information.
When a disc records video images of great personal value, the user may provisionally determine a reproduction route for the video on the disc with no danger of the valuable images being overwritten or lost.
By defining a plurality of sets of user-defined type chain information, by preforming reproduction of each and then selecting the best for a real edit, the user can perform a bold editing operation that directly rewrites the content of the video objects on the optical disc. While the original video objects will be lost, the user will have had ample chance to confirm the result of the real edit and so should be satisfied with the result.
The third object of the present invention can be achieved by a video data editing apparatus that uses an optical disc as an editing medium, the optical disc including: a data area for recording a file including at least one video object; and an index area for recording original type chain information and at least one set of user-defined type chain information, the original type chain information managing the file as an arrangement of a plurality of file sections, each file section being indicated by section boundaries that are a combination of any two ofxe2x80x94(a) a start position of a video object, (b) an end position of a video object, and (c) at least one predetermined position within a video object, each set of user-defined type chain information indicating a plurality of file parts in the file and a reproduction route for the indicated file parts, each file part being indicated by part boundaries, the part boundaries being any ofxe2x80x94(a) two of the section boundaries, (b) one of the section boundaries and a position in a video object that differs from the predetermined positions, (c) two positions in a video object that differ from the predetermined positions, each reproduction route being independent of an order in which the indicated file parts appear in the file. The video data editing apparatus includes: a reception unit for receiving an operation from a user; a processing unit for processing the file, when the reception unit has received an indication of a real edit operation for one of the sets of user-defined type chain information recorded on the optical disc, so that starting and ending part boundaries indicated in the indicated set of user-defined type chain information become boundaries of the video objects recorded on the optical disc; and an updating unit for updating, after processing by the processing unit, the indicated set of user-defined type chain information in the index area to convert the indicated set of user-defined type chain information into the original type chain information.
Each video object may include a plurality of video object units, each video object unit including a plurality of sets of picture data that are reproduced for a plurality of video frames for a certain reproduction period, and each set of cell information may include: time information including a presentation start time information and presentation end time information for video data in a cell, the presentation start time information showing a display video field of a set of picture data that should be reproduced first in a part of a video object and the presentation end time information showing a display video field of a set of picture data that should be reproduced last in the part, and the cell being one of a file section and a file part; and identification information for indicating the video object to which the cell belongs, wherein the reception unit may receive a play indication for one of the sets of user-defined type chain information and wherein the video data editing apparatus may further include: an access position specifying unit for reading, when the reception unit has received a play indication, mapping information and a pair of presentation start time information and presentation end time information from the index area, and for specifying, by searching the mapping information using the presentation start time information and the presentation end time information, a recording position of a start video object unit including picture data that is displayed for the presentation start time information and a recording position of an end video object unit including picture data that is displayed for the presentation end time information; and a reading unit for reading a video object unit sequence recorded between the specified recording positions; and a decoding unit for decoding the read video object unit sequence and, for outputting, when part boundaries of a part corresponding to a set of cell information in the indicated set of user-defined type chain information do not match a start position of the start video object unit and an end position of the end video object unit sequence, a decoding result between a first video field and an end video field indicated by the cell information, and for prohibiting output of a decoding result of data before the first video field and data after the end video field.
With the stated construction, the cell information specifies the video parts to be used in the editing to an accuracy of one video field. This means that the parts to be edited can be specified with very high precision.